fork download
  1. #include<iostream>
  2. #include<vector>
  3. using namespace std;
  4. vector<int> findDuplicates(int *a,int n){
  5. vector<int> ans;
  6. for(int i=0;i<n;i++){
  7. int temp = abs(a[i]);
  8. if(a[temp-1] < 0){
  9. ans.push_back(temp);
  10. }
  11. else
  12. a[temp-1] *= -1;
  13. }
  14. return ans;
  15. }
  16. int main() {
  17. int n;cin>>n;
  18. int *a = new int[n+1];
  19. for(int i=0;i<n;i++){
  20. cin>>a[i];
  21. }
  22. vector<int> ans = findDuplicates(a,n);
  23. for(auto x:ans)
  24. cout<<x<<" ";
  25. cout<<endl;
  26. return 0;
  27. }
Success #stdin #stdout 0s 4416KB
stdin
8
7 3 5 2 3 9 1 2
stdout
3 2